Modern Vespa

Want to hookup an audio IC to my Sprint (1968), could you put a transformer onto my 6 volt system to run say a TDA2003? Tap into the lighting system or off the stator?

A simple transformer will not do anything with direct current: it works on AC current, or pulsed DC.

No idea what product youre trying to add, but google the Scootronics Intelli converter. Might work for you.

I'm assuming OP meant this:

https://www.ebay.com/itm/293515827019?var=0&mkevt=1&mkcid=1&mkrid=711-53200-19255-0&campid=5338590836&toolid=10044&customid=286d0d32b08f1e90b51769d9bda38d63

Although why a person would want to attach one to a scooter is beyond me.

I do. But frankly I am at a loss as far as what the OP is trying to do here. This is like saying: "I want to add a resistor to my scooter....". A few more syllables would be helpful. Thanks.

To wire up a sound system. Speakers mounted where glovebox would go and that chip to power it. Then maybe Bluetooth to connect it to my phone.

Any glovebox sized Bluetooth speakers on the market? Charge it at home with option topping up while riding?

Almost as easy would be to add a USB adapter that will run off pretty much any input voltage you can deliver to it. Then just plug your speakers (or any other USB accessories you might care to power) into that and you can power your iPod, too!

iPod click wheel with 32pin connector.

Vintage right there…